AK8779B Datasheet, PDF (3/13 Pages) Asahi Kasei Microsystems – Hall Effect IC for Pulse Encoders

4.1. Block Diagram
VDD
4. Block Diagram and Functions
REGULATOR
BIAS
OSC
VSS
VREG
HE_DRIVE
TIMING LOGIC
[AK8779B]
OUTA
CHOP_AMP
COMP
OUTB
HALL SENSORS
Figure 1. AK8779B Block Diagram
4.2. Functions
Table 1. Circuit configuration
Block Name
Function
REGULATOR
Generate internal operating voltage.
HALL SENSORS
Two Hall elements fabricated by CMOS process.
CHOPPER_SW
Hall sensor drive switch.
Perform chopping in order to cancel the offset of Hall sensor.
CHOP_AMP
Amplify two Hall sensor output voltages with summation and subtraction
circuit.
COMP
Hysteresis comparator.
BIAS
Generate bias current to internal circuits.
HE_DRIVE
Generate bias current for Hall sensors.
OSC
Generate operational clock.
TIMING LOGIC
Generate timing signal for internal circuits.
LATCH & LOGIC
Logical circuits and open drain driver.
015001034-E-02
-3-
2015/10